title: Population-based investigation of familial undescended testis and its association with other urogenital anomalies.
abstract: OBJECTIVE
  Up to now, observation of familial undescended testis (UDT) has been confined to the description of individual cases. The aim of our study was to evaluate the frequency of a positive family history and of associated urological anomalies in family members, and to calculate the risk of newborn male individuals having UDT if a family member is affected.
  
  
  METHODS
  A total of 374 patients who underwent surgery because of UDT and 374 controls without UDT were interviewed by means of a special questionnaire. We asked for a family history of UDT, as well as for other urogenital anomalies (varicocele, hydrocele, hypospadias, testicular cancer, renal anomalies). For statistical analysis the odds ratio was calculated.
  
  
  RESULTS
  Of the analysed patients, 85 (22.73%) had family members with UDT versus 7.5% of the control group. Of these 85 cases, brothers were involved in 37.3%, fathers in 35.2%, uncles in 23.5%, cousins in 16.5%, great-cousins in 8.2% and grandfathers in 7.1%. The risk of UDT in a newborn male is 3.6-fold overall, and 6.9-fold if a brother and 4.6-fold if the father is affected. The rate of family members with UDT and/or other urogenital anomalies in the patient group was nearly 2-fold higher than in the control group.
  
  
  CONCLUSIONS
  Due to the increased familial risk and the higher percentage of a positive family history for UDT and other urogenital anomalies in patients with UDT, a genetic predisposition seems probable.
authors.affiliation: Department of Urology and Pediatric Urology, Philipps-University Marburg, Baldingerstrasse, D-35043 Marburg, Germany. elert@mailer.uni-marburg.de
authors.forename: A
authors.initials: A
authors.lastname: Elert
authors.forename: K
authors.initials: K
authors.lastname: Jahn
authors.forename: A
authors.initials: A
authors.lastname: Heidenreich
authors.forename: R
authors.initials: R
authors.lastname: Hofmann